What is 'anti' about anti-reaches? Reference frames selectively affect reaction times and endpoint variability

Area of Science:

• Neuroscience
• Motor Control
• Human Movement Science

Background:

• Reach movement planning relies on spatial information processed in various reference frames.
• Cortical sensorimotor neurons use eye- or hand-centered frames for target representation.

Purpose of the Study:

• To investigate how eye- and hand-centered reference frames differentially impact kinematic parameters of reach movements.
• To determine the specific effects of stimulus-response compatibility (SRC) within each reference frame on motor planning and control.

Main Methods:

• A generalized anti-reach task was employed to decouple SRC effects in eye- and hand-reference frames.
• Behavioral data on reach reaction times, movement times, and endpoint variability were collected and analyzed.

Main Results:

• Reaction times were affected by SRC in both eye- and hand-reference frames.
• Movement times were solely influenced by SRC in the hand-reference frame.
• Endpoint variability was uniquely affected by SRC in the eye-reference frame.

Conclusions:

• Eye- and hand-reference frames have distinct influences on different kinematic parameters and phases of motor actions.
• Stimulus-response compatibility effects on reaction times are valuable for studying movement planning reference frames.
• Understanding reference frame contributions is crucial for dissecting motor planning and control processes.